William



UNITED STATES PATENT OEEicE.a

winnmita-pasurrmsoncor piucase, ILLINOIS, AssieNoE 'ro 'ri-1E WESTERNELECTRIC COMPANY, or sA-'ME- PLAUE.

TELEG RAPH-CAB LE.

SPECIFICATIGN forming part-of Letters Patent No. 398,442, dated February26, 1889.

Application timmy 18,1387. serai No. 244,602, (Nom-tau.)

To @ZZ whom it may concern.- l lBe it known that I, WILLIAM R. PATTER-sN,.a citizen of. the'United States, residing j at Chicago, in thecounty of Cook and State i of Illinois, have invented a certain new andl y useful Improvement in Telegraph Qables, (Case 73,) of Whiclrthefollowing is fa full, l clear, concise, and exact description, referencebeing had to the accompanying drawings,

1o forming a part of this specification.

My invention relates to telegraph-cables in which the conductors areseparately insulated with a fibrous material and formed into a corewhich i5 pmtectedbv a Water-proof pipe, the i I5 4space remainingin thepipe about and among the conductors being filled with an insulatingmaterial which is preferably forced in charged with gas. Heretofore inthis class of electric cables the core has been formed by twisting 2othe insulated conductors together and binding them together by a strongserving, the conductors being compressed by a die just before theserving as the serving is being wound'on. In this manner theelectrostatic capacity of the cable is greatly increased and itsusefulness thereby impaired.

My invention consists in simply loosely twisting the conductors togetherand dispensing with the serving, so that the core, when 3o surrounded bythe lead pipe, will substantially. fill the same, and the wires, beingonly twisted loosely together, the insulating filling l of paraffine orother substance will become solid asl it cools and fill, as it were, inmass 3 5 the spaces between the different wires.

Heretofore the, paraine that has been forced in has mostly formed in anannular ring about the core, the core itself being penel' traten to onlya slight extent by the suing. i

4o In order to thoroughly saturate the tibrous covering, it has beennecessary to soak the core in insulating material before the core isdrawn into the pipe.

According to my invention -herein, it will '1 be selen that allunnecessary compression of the fibrous covering of the core is avoided,and the conductors are soevenly distributed and uniformly protected thatthe electrostatic capacity of the cable is greatly reduced and g at thesame time made more uniform, thus 5t increasing greatly the utility ofthe cable.l

vThe methods and apparatus employed in manufacturing the cable hereindescribed are claimed in other applications filed herewith, and willtherefore be referred to herein only incidentally. It is evident Vthatonly comparatively short lengths of a loosely-twisted core of finewires'without a serving could be pulled into a lead pipe Without injuryto the conductors, unless the lead pipe were much 6o larger than thecore. Therefore, while it is practicable to make my cable hereindescribed by this old method ofY drawing in -thecere ii'- would beexpensiveand liable to causejsome slight injury to the conductors. ltherefore preferably use the. method described inmy `application of evendate herewith, No. 244,601.

Having thus briefly indicated some of the processes by which myinvention herein may 'l be carried out, I will refer to the drawings, in7o which- Figure l is an enlarged section of my cable.

Fig. 2 is a side view of the slightly-twisted core. The pipe o., it willbe seen, incloscs thecore,

, the different wires, b, of the core being scparately insulated byfibrous covering c. The: dierent insulated conductors, it will be seen,are not closely pressed together, as heretol fore, but are so disposedthat the spaces 8o among them and between the interior of the pipe andthe outside wires will be substani tially uniform. Thus, when theinsulatingg filling d, of paraiiine or other substance, isl

forced in, it will distribute it^elf not only about the core, but alsoto a certain extent in mass among the conductors, and. thus, with agiven-sized pipe, the conductors will arrange themselves so as toutilize the whole space within the pipe, and, none ofthe con- 9o ductorsbeing closely compressed together, as

heretofore, the cable will be of very low electro-- static capacity-aslow as is consistent with the size of the pipe. 4

Havingthus described my invention, I claim 9 5 as new and desire tosecure by Letters Patent- As zg new article of manufature, a cableeonsising of an unserved core of separatelyinsulatef conductors slightlyand loosely visted together, an exterior pipe inclosing said core, and alling of insulating material forced int-o the pipe among and around theconuctors of the com, said insulating-filling being sodied when mld, likpamfne.

WILLIAM R. PATTERSON.

`\\' im esscs:

GEORGE P. BARTON. WM. M. QILLER.

